> I don't think Adobe and Microsoft, the two biggest third party Mac developers, care what Apple imposes on the Mac App Store.
Microsoft must care somewhat because they have spent a lot of time fully sandboxing Office 2016. Since OneNote is already available in the MAS [1], I reckon Microsoft will eventually add the remaining Office apps at some point in the future.
> I think Office for Mac is not yet fully 64-bits
Microsoft released the first 64-bit version of Office 2016 for Mac (15.25.0) last month [2] [3]